Stack Space & Ackermann

[Era Scarecrow via Digitalmars-d-learn]

On Thursday, 5 January 2017 at 04:53:23 UTC, rikki cattermole 
wrote:
> Well, you could create a fiber[0].
>
> Fibers allow you to set the stack size at runtime.
>
> [0] http://dlang.org/phobos/core_thread.html#.Fiber.this

  Well that certainly does seem to do the trick. Unfortunately I 
didn't get the next output because I ran out of memory to 
allocate/reallocate over 2Gb :P

  I suppose with a 64bit compiling the program might run a bit 
longer and succeed further (with 24Gigs of ram), however the 
sheer amount of memory required will make this little exercise 
more or less a waste of time.

  Still that was an interesting way around the (stackframe) 
problem, one I'll keep I mind (should i need it again).

void m() {
     foreach(i; iota(6))
         foreach(j; iota(6)) {
             writefln("Ackerman (%d,%d) is : %d", i,j,ack(i,j));
     }
}

int main(string[] args) {
     Fiber composed = new Fiber(&m, 2<<28); //512MB
     composed.call();

     return 0;
}

results:

Ackerman (3,5) is : 253
Ackerman (4,0) is : 13
Ackerman (4,1) is : 65533

core.exception.OutOfMemoryError at src\core\exception.d(693): Memory 
allocation failed